Classically, the transfer of oxygen to tissue locations in humans and other vertebrate animals has been defined as being functionally dependent upon red blood cell (RBC) flux associated with the tissue, specifically the flow rate and hematocrit of RBCs, and upon the difference in oxygen content between arterial and venous RBCs. Further, the amount of oxygen transfer from the flow of other components of the circulatory system, such as plasma, typically has been a negligible fraction of the total oxygen delivered by the RBCs. Normally, RBCs contain about 98% of the arterial oxygen content. Thus, a condition leading to a localized, regionalized and/or systemic reduction in the circulation of RBCs, often resulting from a blood vessel constriction or occlusion, or from a reduced number of normal RBCs in the cardiovascular system, can result in local, regional or systemic tissue hypoxia, tissue death and possibly even in the death of the human or other vertebrate.
Current methods for treating many causes of tissue hypoxia, particularly hypoxia resulting from a reduction in RBC flow, are typically ineffectual and/or require long, time-consuming procedures before restoring adequate oxygen delivery to the hypoxic tissue.
Therefore, a need exists for a faster more effective method of delivering oxygen to hypoxic tissue having inadequate RBC flow.
The present invention relates to a method for increasing organ function of a vertebrate, while the organ has reduced red blood cell flow due to a least one partial obstruction of a blood vessel within the circulatory system of the vertebrate, and wherein the vertebrate has a normovolemic blood volume and at least a normal systemic vascular resistance, comprising introducing hemoglobin into the circulatory system of the vertebrate, at least one dose of hemoglobin, thereby increasing function of the organ.
This invention has many advantages, including reducing the probability and extent of organ hypoxia, and of possible tissue necrosis, resulting from at least a partial reduction in RBC flow. Another advantage is improved survivability for a vertebrate suffering from a significant reduction in RBC flow to a vital organ or portion thereof. This invention also allows the performance of invasive procedures, which require restriction of RBC flow, without significantly reducing oxygenation of distal organ tissue.